When MacLeod and Richie are witness to a terrorist attack on an Ambassador, Richie dives in like a Superhero, cocky with Immortality. In the resulting confusion, one of the terrorists is killed, and another, Annie Devlin, an Immortal, is captured. She swears revenge on Richie, and when she escapes from custody, MacLeod takes on the task of educating Richie so that he will have a chance in combat against her. Meanwhile, Flashbacks reveal an earlier friendship between MacLeod and Annie. Mac renews the friendship, and the two Immortals who have both recently lost their lovers find solace in one another. In the end, Richie defeats Annie but can't bring himself to kill her, and MacLeod convinces her to pursue the blood debt no further.

Charlie and MacLeod come to the aid of Sara Lightfoot, an Indian woman on the run with a baby. She tells them Avery Hoskins is trying to steal her baby. Hoskins and his brothers come after them, and they are forced to flee overland. After a rugged flight through a mountain canyon, MacLeod learns that the baby is in fact Hoskins' son, taken by Sara in retribution for her own child, killed by runoff from Hoskins' mines.

MacLeod feels the Buzz coming from an ancient sarcophagus and opens it to find Nefertiri, Cleopatra's handmaid, buried 2000 years ago with her mistress. Now revived, she pursues a vendetta against the Immortal Marcus Constantine, who was her lover and her enemy. Mac believes Constantine, who claims that he no longer wishes to fight Nefertiri -- this former Roman General has turned his back on battle and is now a curator, working to preserve history and its lessons. But Nefertiri can't let go of the old grudge, and for the first time, MacLeod is forced to face a woman he loves in Immortal combat.

When a valuable DaVinci sketch is stolen from a friend of MacLeod's in a robbery that killed two guards, MacLeod offers to act as go-between to ransom it back. He discovers the sketch was stolen by Kagan, an Immortal he faced once before, when Kagan was a bank robber in 1930 Paris and MacLeod killed his mentor. Meanwhile, Maurice asks MacLeod to talk to his troubled niece, Simone. Simone turns out to be more troubled than Maurice knows -- she's a prostitute and Kagan's accomplice. MacLeod goes after Kagan, who protests his innocence in the deaths of the guards and who promises MacLeod that he'll change his ways if MacLeod will help him. When Simone, the only one who knows Kagan is the killer, is killed, MacLeod realizes that Kagan could never really change and confronts Kagan, taking his head.

Running for his life from Immortal Terence Kincaid, Kenny runs straight into Anne Lindsey's emergency room. Stashing Kenny in the hospital chapel, Anne calls MacLeod for help. MacLeod agrees to harbor him for one night only, but when MacLeod gets him home, Kenny discovers his long-lost teacher there -- Amanda!